Modular insulated heating element supports

ABSTRACT

A modular electric heating wire support device which includes a plurality of substantially similar insulating support members each having a through-hole for accommodating the resistance wires and an elongated slot. The support members are strung on an elongated relatively rigid strap which passes through the slots in the support element, the ends of the straps being secured to a main frame.

United States Patent 1 Kelley MODULAR INSULATED HEATING ELEMENT SUPPORTS [76] Inventor: Winfield L. Kelley, 1803 Granada B1vd., Coral Gables, Fla. 33134 [22] Filed: Mar. 28, 1974 [21] Appl. No.: 455,907

152] [1.8. CI. 219/550, 174/138 J, 219/532, 219/536, 338/213 [51] Int. Cl. 1105b 3/02 [58] Field of Search 174/138 .1; 219/532, 536, 219/550, 552; 338/213; 339/220 R [56] References Cited UNITED STATES PATENTS 795,803 7/1905 Vedovelli 338/213 1,489,843 4/1924 Maclnnes 1 219/550 X 1,514,858 11/1924 Maclnnes 219/532 1,679,841 8/1928 Shaw 219/532 1,775,441 9/1930 Pipes 174/138 J 2,963,539 12/1960 l-lynes 174/138 J [451 Oct. 15, 1974 3,036,187 5/1962 Goldstaub ct a1 219/550 X 3,045,097 7/1962 Sellers 219/550 X 3,718,806 2/1973 Potter 219/550 FOREIGN PATENTS OR APPLICATIONS 321,503 11/1929 Great Britain 219/550 503,495 4/1939 Great Britain 833,045 4/1960 Great Britain "212/5511 Primary Examiner-Velodymyr Y. Mayewsky Attorney, Agent, or Firm-Stevens, Davis, Miller & Mosher 5 Claims, 4 Drawing Figures PATENTEU I 51974 3.842.244

SHEET 10F 2 FIG.2A

MODULAR INSULATED HEATING ELEMENT SUPPORTS The present invention relates to electric heater construction, and more particularly to the insulator supports on which resistance wire heating coils are mounted.

The system of this invention utilizes ceramic insulators which are strung on a metal strap incrementally to obtain any desired length of support and any number of such support units may be incorporated into the heating unit, depending on such factors as design and economic considerations.

Modular-type support elements are known in the prior art and examples of some to these can be found in US. Pat. Nos. 1,433,932 to Bovard; 1,679,841 to Shaw; 1,775,441 to Pipes and 2,963,539 to Hynes. The support structures exemplified by these patents consist basically of a number of complementary elements having complementary surface grooves or semi-spherical surface openings which when joined with the complementary part define a complete opening through which a resistance wire coil can pass. The sets of complementary members are secured on a long cotter pin (e.g.,

Shaw) or shaft (e.g., Bovard) and the complete unit is in turn secured to a frame member.

One of the problems associated with these prior art type of support members lies in their lack of flexibility and capability for expansion when subjected to the heat generated by the resistance wire elements. This is due to the fact that the complementary members must be clamped tightly against each other in order to ensure that the resistance wire coils will be securely held and supported. This lack of flexibility also subjects these prior art devices to increased possibility of breakage in the case of their being jarred or otherwise subjected to heavy vibrations. If, on the other hand, the complementary members were only loosely supported on the mounting rod or pin, there would result an increased possibility that the supported resistance wires, especially in the case of straight (uncoiled) or small-coiled wires, would work loose from the complementary grooves and fall off the supports.

The present invention is designed to overcome these problems associated with prior art devices by providing a modular support system which is flexible enough to absorb normal shocks and permit expansion due to heat while at the sametime being capable of securely supporting any size resistance wire. The support system of this invention basically consists of a number of substantially identical rectangular support blocks, each divided into essentially two halves with an elongated slot formed in one half and a hole drilled through the other half. A mounting strap passes through the elongated slots and any number of support members can be strung on the mounting strap to form a complete modular unit, the number being limited only by the length of the strap or the dimensions of the overall support frame itself. Several modular units are fixed to a support frame in spaced relation to each other and a resistance wire is then strung through the holes in the support members to complete the heater unit.

By constructing the support members as described above, they can be strung on a mounting strap in alternating relationship with the heating element support holes of adjacent members being on opposite sides of the strap to provide a symmetric assembly which also aids in keeping the resistance wires apart in the event that one support member should break. Under normal circumstances, any breakage of a support member would occur only in the half portion in which the wire supporting hole is formed; it is unlikely that breakage would occur in the half in which the elongated slot is formed and therefore the original separation of the support members can be maintained even upon the occurrence of the breakage of one member.

BRIEF DESCRIPTION OF THE DRAWING A preferred embodiment of the invention will be described with reference to the attached drawing figures, wherein:

FIG. 1 shows one set of insulating support members mounted on a mounting strap;

FIG. 2 shows an exploded view of two adjacent insulating support members strung on a mounting strap;

FIG. 2A shows a plan view of two adjacent support members; and

FIG. 3 shows a completed unit mounted on a main frame assembly.

DESCRIPTION OF THE PREFERRED EMBODIMENT The support system of this invention comprises a number of substantially identical ceramic insulating support members 2 each having a through-hole 4, through which a resistance wire heating coil 6 can be threaded, and an elongated slot 8 through which a support strap 10 is threaded. The slots 8 are dimensioned larger than the strap 10 to permit a small amount of lateral and rotational movement of the mounted support members.

The individual insulating supports can be made of any suitable material and particularly any well-known ceramic insulator material. The supports may be manufactured by any suitable pressing technique by which the slots 8 can be formed simultaneously; the throughholes 4 are drilled after the supports have been pressed into shape.

In the preferred embodiment, the support members have a rectangular cross-sectional shape and for the sake of descriptive convenience will be considered as having a major or long axis L which bisects the rectangle in the long direction and a minor or short axis S which bisects the rectangle in the short direction. The elongated slot 8 is formed in the support member to pass through the member in a plane substantially parallel to that of the rectangular cross section and on one side of the short axis S; the through-hole 4 is drilled through the support member on the opposite side of the short axis from the slot 8, the central axis of the through-hole 4 being substantially normal to the plane of the rectangular cross section.

This construction of the individual support members is preferred in order that a completed module (FIG. I) will have a substantially symmetric appearance. At the same time, this permits maximum spacing between the resistance wire coils in the case of an alternate mounting arrangement of adjacent support members to have their through-holes located on opposite sides of the strap 10. The completed module also incorporates end pieces 12 which are made of the same ceramic material as support members 2 and are manufactured in the same manner except that they consist only of the half portion of the support member 2 containing the elongated slot 8.

The mounting strap can be of any suitable metal (or other material) having sufficient rigidity to support the support members 2 while at the same time being bendable at its respective ends'to both limit the movement of the support members along the strap and to allow the strap to be fastened to a main frame. The strap 10 has holes 14 spaced at intervals therealong to permit the strap to be bent at any of a number of positions and secured to the main frame at the hole closest to the bend.

A complete unit incorporating several modules is shown in FIG. 3. In the completed unit, the straps 10 are mounted to upper and lower frame members 16, 18 by nut and bolt arrangements or any other appropriate fastening means and are spaced from each other along the length of the frame members. One or more resistance wire heating elements 6 is then strung through the holes in the support members, for example in an S- like arrangement. When assembling completed units in a heater, the ends of the wire heating elements are, of course, connected to suitable terminals not shown.

The advantages of the improved heater coil support device of this invention are several. First, the individual ceramic insulating support members have simple shapes and can therefore be manufactured by conventional pressing techniques with ease; further, since each support member is a complete unit by itself, a complete module can be constructed without regard to the pairing requirements associated with prior art devices. Still further, because the support members do not interlock with each other, they can remain flexible to absorb minor shocks and to provide room for expansion when heated. Still further, using a flat strap as the mounting member 10 provides the necessary rigidity for the complete unit and prevents undue rotation of the support members.

It is to be understood that various modifications in the structural details of the preferred embodiment described herein may be made within the scope of this invention and without departing from the spirit thereof. It is intended that the scope of this invention shall be limited solely by the hereafter appended claims.

What is claimed is:

1. Apparatus for supporting resistance wire heating coil elements for use in electric heaters, comprising:

a plurality of resistance wire insulating support members, each member having an elongated cross section, a hole, large enough to accommodate a resisj tance wire heating element, formed in and passing through said member in a direction substantially normal to the plane of said elongated cross section and offset to one side of the center of said member, the periphery of 'said hole being circumferentially completely surrounded by the body of said support member, and an elongated slot passing through said member in a direction substantially parallel to the plane of said cross section and offset to the opposite side of the center of said member from said hole;

a frame; and

a mounting member extending through said elongated slots in said support members, said mounting member having respective end portions fixed to said frame for fixedly mounting said support members to said frame;

, wherein each support member is mounted on said mounting member independently of each other support member to permit relative longitudinal and lateral movement between adjacently mounted support members, said support members being disposed on said mounting member such that the resistance wire accommodating holes in adjacent support members are located on opposite sides of the longitudinal axis of said mounting member.

2. The apparatus according to claim 1, wherein said mounting member comprises an elongated flat straplike member.

3. The apparatus according to claim 2, further comprising: a plurality of said mounting members, on which said support members are mounted in a similar manner, fixed to said frame; and at least one elongated resistance wire threaded through the holes in said support members.

4. The apparatus according to claim 2, wherein said support members each have a substantially rectangular cross section having long and short substantially perpendicular bisecting axes, wherein said hole is formed in said support member such that the central axis thereof lies to one side of the short bisecting axis of said cross section, and wherein the longitudinal axis of said elongated slot extends substantially parallel to said short axis and on the opposite side thereof from the central axis of said hole.

5. The apparatus according to claim 2, wherein said support members are constructed of pressed, heatinsulating ceramic material. 

1. Apparatus for supporting resistance wire heating coil elements for use in electric heaters, comprising: a plurality of resistance wire insulating support members, each member having an elongated cross section, a hole, large enough to accommodate a resistance wire heating element, formed in and passing through said member in a direction substantially normal to the plane of said elongated cross section and offset to one side of the center of said member, the periphery of said hole being circumferentially completely surrounded by the body of said support member, and an elongated slot passing through said member in a direction substantially parallel to the plane of said cross section and offset to the opposite side of the center of said member from said hole; a frame; and a mounting member extending through said elongated slots in said support members, said mounting member having respective end portions fixed to said frame for fixedly mounting said support members to said frame; wherein each support member is mounted on said mounting member independently of each other support member to permit relative longitudinal and lateral movement between adjacently mounted support members, said support members being disposed on said mounting member such that the resistance wire accommodating holes in adjacent support members are located on opposite sides of the longitudinal axis of said mounting member.
 2. The apparatus according to claim 1, wherein said mounting member comprises an elongated flat strap-like member.
 3. The apparatus according to claim 2, further comprising: a plurality of said mounting members, on which said support members are mounted in a similar manner, fixed to said frame; and at least one elongated resistance wire threaded through the holes in said support members.
 4. The apparatus according to claim 2, wherein said support members each have a substantially rectangular cross section having long and short substantially perpendicular bisecting axes, wherein said hole is formed in said support member such that the central axiS thereof lies to one side of the short bisecting axis of said cross section, and wherein the longitudinal axis of said elongated slot extends substantially parallel to said short axis and on the opposite side thereof from the central axis of said hole.
 5. The apparatus according to claim 2, wherein said support members are constructed of pressed, heat-insulating ceramic material. 